I added a lot more ginger, and used eggs. I also made a glaze to go over the top with candied ginger pieces. It's dense and moist, and got compliments from the non-gluten-free people, too. Most of the rising happens when you add the boiling water. I struck it into a smaller pan so it would be deeper, and it still baked for the same time.

Reviewer:

I don't typically review recipes that I've altered from the printed, but since this one has no reviews, I'll do it anyway :)
This turned out really good for vegan, gf gingerbread. I changed the flour combo as I don't keep amaranth around. So I used a combo of sorgum, buckwheat, brown rice, potato starch and coconut flour. I subbed the agave syrup for honey straight across.
Not sure why the baking soda was in such a high measurement and wonder if it would have been better to decrease this and add some baking powder, but it did rise a little (mostly around the outside edges).
Very happy to have stumbled upon this recipe as I have wanted gingerbread for a couple years now :) I will definitely make it again, but probably keep the buckwheat measurements the same in my next batch. I am guessing it adds a bit to the overall product.
It tastes best cooled completely in my opinion.